Roller bearing with cylindrical rollers

ABSTRACT

A roller bearing having cylindrical rollers between inner and outer coaxial rings, each of the rings being an integral piece, is fully loaded by insertion of cylindrical rollers through a feed notch. To retain the cylindrical rollers against dropping back through the feed notch, a retaining ring closed in a loop is provided to rest on or in a rim retaining the rollers axially and having the feed notch. The retaining ring, which can also have a sealing part closing the end of the bearing, is mounted such that the retaining ring, the sealing ring and/or a filler piece adapted to fit directly in the feed notch, rests against the open end face of the cylindrical rollers behind the feed notch. The process by which the bearing parts are assembled and secured includes the steps of filling the inner ball race tracks, axially assembly the inner and outer rings, and inserting the rollers for the final ring through a feed notch, thereby axially restricting displacement of the inner and outer rings, and finally retaining the rollers in place by means of the retaining ring. The retaining ring and filler piece can be of metal or relatively harder plastic; the sealing ring can be of relatively softer plastic appropriate for seal packing.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to roller bearings, and in particular to bearingswith one or more rows of cylindrical rollers or "balls". The bearing hasintegral one-piece inner and outer ball race rings equipped with lippedrims confining the rollers to raceways and keeping the roller axes andbearing axis parallel. At least one of the rims has a feed notch forreceiving rollers during assembly, and at the feed notch means areprovided which prevent any of the cylindrical rollers from dropping outof the raceway into the feed notch.

2. Prior Art

According to the needs of a particular application, roller bearings withcylindrical rollers are known in various different configurations.However, bearings with cylindrical rollers always require some means toensure that the cylindrical rollers remain with their axes parallel.Roller bearings of this type are possible with an outer ball race ringhaving two rims confining the rollers and a rimless inner ball race, orvice-versa. For cylindrical roller bearings which are to be used asfixed bearings capable of bearing forces in one or both directions alongthe axis of rotation (i.e., longitudinal forces with respect to a shaftcarried in the bearing), such bearings to date have had three sections.Cylindrical rollers for such axially-loadable bearings are carriedbetween the ball race rings and are confined by rims formed thereon. Inorder to load the raceway between the bearing rings with the cylindricalrollers, one ball race ring is equipped with two rigid rims and theother ball race ring is equipped with one rigid rim, so that thecylindrical rollers can be inserted. Either a loose rim disc or aseparate thrust collar is then added and defines a fourth rim forconfining the balls against the single rim ball race ring. Anotherpossibility for loading the raceway requires that each of the ball racerings be manufactured in integral pieces, each having opposed fixedrims, one of the ball races then being split, and both sections at thesplit being fastened together again with additional fastening devices,after insertion of the cylindrical rollers.

An attempt to surmount these difficulties is disclosed in U.S. Pat. No.1,212,253. In that patent, the means to prevent the cylindrical rollersfrom moving from a raceway into a feed notch consists of an expandingspreader ring. This solution has the disadvantage that at a given outerdimension of the bearing, the cylindrical rollers must be made axiallyshorter by the size of the expanding spreader ring. The carryingcapacity of such bearings is therefore smaller than for bearings withoutan expanding spreader ring. Another disadvantage of such an expandingspreader ring is that both the recess in the race ring and the expandingring must be manufactured with the greatest precision because theexpansion ring has to function as the rim that controls the axialposition of the rollers to keep their axes parallel. Manufacturetherefore is a very complicated process which practically cannot beperformed on an industrial basis because the expanding spreader ringmust ensure such exact control of the rollers.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a simple but reliable meansto prevent dropping of cylindrical rollers into a feed notch of abearing, which can be used with open or closed bearings.

This and other objects are achieved according to the invention by abearing with a retaining ring for retaining the rollers in the raceway,the retaining ring resting on a notched one of the rims and theretaining ring being mounted on the bearing to bear directly orindirectly against an exposed end face of the cylindrical rollers.

The principals of the invention can be embodied in many differentvariations. With bearings open to the outside, the retaining ring ispreferably shaped as a self-contained ring of elastically resilientmaterial, pressed against the cylindrical rollers such that theretaining ring bears directly against the end faces of the cylindricalrollers. The elastically resilient retaining ring is preferably of sucha character that it deforms when pushed into place and springs back wheninserted, thereby adapting as much as possible to the shape of the rigidrim on the race ring. The elastic rim is thereby immovably fastened tothe rigid rim.

In the case of bearings closed to the outside, that is in the case ofsealed bearings, the invention is embodied such that the retaining ringand a sealing ring are connected to one another, or are formed as anintegral piece, for example of a plastic material. The retaining ringmay thereby consist of harder or reinforced plastic, and the sealingring of softer plastic. For sealed bearings, the sealing ring may bedisposed on the retaining ring, whereby the retaining ring by means ofan angled edge can be used to secure the sealing ring.

For the embodiment of the invention with the retaining ring connectedwith the sealing ring, the retaining ring does not have to rest fullyagainst the face of the cylindrical rollers. The retaining ring can beconnected to the sealing ring such that the retaining ring is spacedfrom an edge of the sealing ring and indirectly secures the cylindricalrollers in the area of a feed notch or notches such that the cylindricalrollers are restricted against dropping into the notches. The particularmeans locking the retaining ring and the sealing ring in position on theone of the rims can also be varied.

For open faced bearings, a retaining ring in the form of a closed-overloop of material can be shrunk on or otherwise inserted with an initialradial stress. This is especially effective if the surface of the rigidrim to receive the retaining ring is of convex shape, which with theinitial stress mounting of the retaining ring ensures exact positioningof the retaining ring. One or several locking grooves can be providedfor receiving protrusions of the inserted ring. This locking means isespecially advantageous when immovably mounting the sealing ring, forexample of plastic, which has cold extrusion capabilities and elasticitythat in some instances renders further retaining means unnecessary.

According to another characteristic of the invention, integration of aretaining ring and a sealing ring can be achieved in a simple mannerthrough use of a two-component structure, one zone of the sealing ringconsisting of a harder plastic than the remainder of the sealing ring.According to another preferred embodiment of the invention, the feednotch can be sealed by a filler piece, which is disposed in the feednotch and is held in place by the retaining ring, the filler pieceand/or retaining ring bearing against the end face of the cylindricalrollers. According to another embodiment of the invention, the sealingring, retaining ring and filler piece may be made as a structural unitwhich can be attached to the bearing.

This invention concerns not only the cylindrical roller bearing product,but also a process by which the retaining ring, and preferably also thesealing ring, are mounted. These rings are mounted such that theretaining ring, sealing ring and/or filler piece, with an edge facingthe cylindrical rollers, are positioned to hold the rollers exactlyparallel, reaching just to the same height as the rigid rim otherwisecontrolling the parallel positioning of the cylindrical rollers.According to the invention, this takes place such that the retainingring and/or the sealing ring, preferably with the filler piece, areinserted in a direction parallel to the axis and just up to thecylindrical rollers which rest against the rim, thereby avoiding axialplay by supporting the bearing rollers. These and other characteristicsof the invention are disclosed an claimed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

There are shown in the drawings detailed structural examples ofpreferred embodiments of the invention, which is also capable ofembodiment in additional embodiments. In the drawings,

FIG. 1 is a partial cross section of a double row bearing havingcylindrical rollers, showing a feed notch and a retaining ring;

FIG. 2 is a partial side view of the bearing of FIG. 1;

FIG. 3 is a schematic illustration of an initial stage of bearingassembly;

FIG. 4 illustrates loading a second row of cylindrical rollers after theinner and outer ball race rings have been axially joined;

FIG. 5 illustrates insertion of the closed retaining ring, therebyeliminating the possibility of axial play of the bearing;

FIG. 6 is a partial section view of a roller open on the outside, with acylindrical roller track having a retaining ring inserted in place;

FIG. 7 is a partial section view of a retaining ring combined with asealing ring, which combination comprises a two-component plasticmaterial;

FIG. 8 shows a combination of sealing ring and retaining ring, with aseparate filler piece;

FIG. 9 is a partial side view of a bearing section showing the directionof friction pressure extended on the filler piece by the retaining ring,the friction pressure being indicated by arrows;

FIG. 10 illustrates an embodiment of the invention wherein the retainingring bears indirectly against the end face of the cylindrical rollersand where the filler piece is made of reinforced plastic;

FIG. 11 is a three part combination of sealing ring, retaining ring andfiller piece, wherein the filler piece is of the same material as thesealing ring;

FIG. 12 is a bearing open to the outside with a non-planar rim surface;and,

FIG. 13 illustrates another embodiment of the open bearing of theinvention, with indirect pressure from the retaining ring applied to therollers through the filler piece, and wherein the filler piece comprisesa different material from the retaining ring and includes additionalaxial restriction in the form of a supporting projection.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

According to the invention and the embodiments thereof as shown in thedrawings, a double row bearing with cylindrical rollers is assembled asillustrated in FIGS. 1 to 5. The bearing has inner and outer ball racerings 1 and 2. The inner ball race ring 1 has two lipped outer rims 13,and a center rim 12. The outer ball race ring has only a center rim 22.At least one of the outer rims, for example the left rim 13 in FIG. 1,has a feed notch 10 for receiving rollers 3. If the outer ball race ringhas a lipped outer race rim 23, as illustrated in FIG. 6, then lippedouter race rims 23 on both rings can be provided with a feed notchhaving a contour adapted to receive individual cylindrical rollers.

The cylindrical roller bearing as illustrated in FIGS. 1 to 5 isassembled such that the cylindrical rollers 30 are placed in a firsttrack of the inner ball race ring 1. The outer ball race ring 2 is thenslipped axially over the inner ring 1 and its fully-complemented firsttrack (as shown in FIG. 3). The cylindrical rollers 3 for the secondtrack are then inserted one at a time through the feed notch 10 untilthe second track is also fully complemented with rollers. During thisprocess, the rollers are constrained to remain parallel and possibilityof axial play between the inner and outer race rings of the bearing iseliminated by means of the resulting bracing of the inner and outer racerings against the end faces of the cylindrical rollers. This bracing isindicated by arrows in FIG. 5.

The retaining ring 4 closes the feed notch 10 against escape of thecylindrical rollers. The retaining ring 4 can be bent from a flat steelband and can be welded into a loop. Retaining ring 4 is placed on rim 13under pressure. Being forced onto rim 13, the retaining ring 4 stretchesand when its final position is obtained, adapts to the shape of the rim,thereby ensuring secure positioning. The bearing with cylindricalrollers as illustrated in FIG. 1 to 5, when fully complemented andprovided with the retaining ring 4, is absolutely self-secured. Thebearing cannot fall apart after assembly, and none of the cylindricalrollers can move out of their track.

FIG. 6 shows a single roller bearing. The outer ball race 2 has a largerwall thickness and two outer race rims 23. Furthermore, feed notches 10and 20 are provided in each of the rims 13 and 23, on the inner andouter rings, respectively. Unlike the initially-described embodiment inwhich a retaining ring bears radially inwardly on the inner race 1, theretaining ring 42 is now attached to the rim 23 of the outer ball race 2in a manner like that described above.

FIG. 7 shows a cross section of a closed bearing, wherein the retainingring 42 consists of plastic, for example a reinforced polyamide, and iscombined with a sealing ring 5 closing the space between rings 1 and 2.Both parts 5 and 42 can be formed integrally, and preferably in thatcase the sealing ring 5 consists of relatively softer material, forexample, polyurethane elastomer.

Assembly and prestressed insertion of retaining ring 42 as combined witha sealing ring are done in the same manner as shown in FIGS. 3 to 5. Theretaining ring 42 resiliently holds itself in place and a part extendsinto the recess 11 of the inner ball race. Another embodiment of aclosed bearing is shown in FIGS. 8 and 9. In this embodiment theretaining ring 42 is shown with an outer angular edge 40. The sealingring 5 is placed on the retaining ring before assembly and insertedtogether with the retaining ring. The filler piece 50 for closing thefilling notch does not require special mounting support, and may be heldin place by the frictional pressure of the retaining ring 42.

FIG. 10 shows another combination according to the invention, includingthese parts. The sealing ring 5 of relatively softer material is rigidlyconnected with the retaining ring 41, made of a harder plastic. Thisembodiment is arranged such that the plastic retaining ring 41 onlyindirectly provides axial restriction of the cylindrical rollers 3, dueto ring 41 supporting the filling piece 50 and the latter bearing on thecylindrical rollers. Good mounting support for the filler piece 50 isensured by means of a concave or convex shape of the contact surface 14,thereby tending to keep the retaining ring in place. Before or afterassembly the filler piece can be welded to the retaining ring is asimple manner.

In the embodiment shown in FIG. 11, the retaining ring 42 directlysecures the cylindrical rollers 3. In this respect, the embodiment ofFIG. 11 is similar to the embodiment of FIG. 7. The filler piece 50consists of soft packing or sealing material and is also held in placeby the frictional pressure of the retaining ring.

FIGS. 12 and 13 illustrate another open bearing embodiment, with aretaining ring formed of a closed band of material. In FIG. 12, theretaining ring 42 is pushed onto the arched convex surface 14 of the rim13. By this structure alone the retaining ring is sufficiently held inplace in direct contact with the end faces of the cylindrical rollers 3,to prevent their escape through the loading notch.

It is also possible in a similar embodiment to use indirect contact ofthe retaining ring 41, for exerting the necessary restriction againstthe end face of the cylinder rollers 3. FIG. 13 shows a retaining ring41 with a pocket 43 and a projection on the filler piece 50, whichensures a secure connection between retaining ring 41 and filler piece50.

Details of the individual embodiments are partially interchangeable, andexemplary rather than exhaustive groupings are shown herein. In place ofrecesses 11 to further secure retaining ring 42, other forms ofunevenness, for example roughened surfaces, ribs or similar unevenfeatures may be provided. The selection and type of structuralconnections depend to some extent upon the individual types of bearingsand their particular applications. In each embodiment except that ofFIG. 6, the retaining ring is inserted over one of the rims and bearsinwardly. As shown in FIG. 6, however, it is also possible to place theretaining ring inside a rim to bear outwardly in the radial direction.

In multiple row bearings according to the invention, only one of theball races has two outer rims per cylindrical row. If more than twotracks are provided, then all but one of the tracks of a ball race canbe fully loaded with rolls before the other ball race is pushed axiallyover the first. The last track requires only one rim, and with theretaining ring axially secures the whole structure.

The invention having been disclosed, additional embodiments will nowbecome apparent to persons skilled in the art. Reference should be madeto the appended claims rather than the foregoing specification asindicating the true scope of the subject invention.

What is claimed is:
 1. A roller bearing comprising:a plurality ofcylindrical rollers; an integral inner race and an integral outer racefor the rollers, the inner and outer races being coaxial, the racesbeing provided with lipped rims for axial retention of the cylindricalrollers, at least one of the races having a feed notch in an outer oneof the rims, the feed notch to be blocked to prevent dropping out of therollers into the feed notch; and, a retaining ring blocking the feednotch, the retaining ring being disposed on one of the rims and bearingdirectly against an exposed end surface of the cylindrical rollers atthe feed notch, wherein the retaining ring is closed on itself andcomprises an elastic material and bears directly against the end surfaceof the cylindrical rollers.
 2. A bearing according to claim 1, furthercomprising a sealing ring connected to the retaining ring, the bearingbeing thereby sealed.
 3. A bearing according to claim 2, wherein theretaining ring and sealing ring are connected in one piece and are madeof resilient material.
 4. A bearing according to claim 3, wherein theretaining ring and sealing ring are plastic.
 5. A bearing according toclaim 2, wherein the retaining ring and sealing ring are made of atwo-component plastic material, one component being of a softer plasticmaterial and another component forming the retaining ring being of aharder plastic material.
 6. A bearing according to claim 1, furthercomprising a filler piece mounted in the feed notch and retained inposition by the retaining ring and resting against the face of thecylindrical rollers.
 7. A bearing according to claim 1, wherein theretaining ring is mounted on one of the rims and said one of the rimshas an uneven surface for securing the retaining ring.
 8. A bearingaccording to claim 1, wherein the retaining ring is mounted on one ofthe rims and the surface of the one rim is concave.
 9. A bearingaccording to claim 1, wherein an end of the bearing is closed by asealing ring, the retaining ring and a filler piece being attachedtogether as a structural unit and attached to the bearing.
 10. A bearingaccording to claim 1, wherein a sealing ring, the retaining ring and afiller piece are connected to one another such that the filler piecesecures the cylindrical rollers against escape through the feed notch.11. A bearing according to claim 1, comprising a single row of thecylindrical rollers.
 12. A bearing according to claim 1, comprising aplurality of rows of the cylindrical rollers.
 13. A bearing according toclaim 1, wherein a surface of the one rim holding the retaining ring isconvex.
 14. A process for manufacture of a bearing having cylindricalrollers secured against axial displacement in the area of a feed notchof the bearing, comprising the steps of:providing a integral inner raceand an integral outer race for the cylindrical rollers, the races beinglipped with rims and an outer one of the rims of the races having a feednotch; loading the cylindrical rollers between the races through thefeed notch; attaching at least one of a retaining ring and filler pieceby prestressing such that at least one of the retaining ring, a sealingring 1 and filler piece bear axially against and along thecircumferential extent of exposed ends of the cylindrical rollers at thefeed notch, retaining the rollers in position.
 15. The process of claim14, wherein during insertion of the retaining ring, pressure in adirection parallel to axes of the cylindrical rollers is exerted on saidone of the retaining ring, sealing ring and filler piece and the otherball race on the opposite side is braced.
 16. The process of claim 14,wherein the retaining ring is forced over the rim and exerts an inwardpressure on the rim.
 17. The process of claim 14 wherein the retainingring is forced within the rim, and exerts a pressure outwardly.
 18. Aroller bearing comprising:a plurality of cylindrical rollers; anintegral inner race and an integral outer race for the rollers, theinner and outer races being coaxial, the races being provided withlipped rims for axial retention of the cylindrical rollers, at least oneof the races having a feed notch in an outer one of the rims, the feednotch to be blocked to prevent dropping out of the rollers into the feednotch; and, a retaining ring blocking the feed notch, the retaining ringbeing disposed on one of the rims and bearing directly against anexposed end surface of the cylindrical rollers at the feed notch,wherein a surface shape of the one rim is selected from the groupconsisting of a concave shape and a convex shape.